Quito De La Roque will not run in the Betfred Cheltenham Gold Cup next month.
Trainer Colm Murphy has admitted defeat with the eight-year-old, who was a late absentee from last Sunday's Irish Hennessy, and has taken him out of the race.
He is currently on a course of antibiotics and will now be aimed at the Punchestown Festival.
"We've taken him out as he's got a problem with his sinuses," said Murphy.
"He's on a course of antibiotics and we are just hoping it clears up soon.
"Nothing much has gone right with him this season, but at least it might explain his run in the Lexus.
"We'll look to Plan B now and hope to get to Punchestown."